Plasma-Resistivity-Induced Strong Damping of the Kinetic Resistive Wall Mode

Abstract

An energy-principle-based dispersion relation is derived for the resistive wall mode, which incorporates both the drift kinetic resonance between the mode and energetic particles and the resistive layer physics. The equivalence between the energy-principle approach and the resistive layer matching approach is first demonstrated for the resistive plasma resistive wall mode. As a key new result, it is found that the resistive wall mode, coupled to the favorable average curvature stabilization inside the resistive layer (as well as the toroidal plasma flow), can be substantially more stable than that predicted by drift kinetic theory with fast ion stabilization, but with the ideal fluid assumption. Since the layer stabilization becomes stronger with decreasing plasma resistivity, this regime is favorable for reactor scale, high-temperature fusion devices.

Combined effects of trapped energetic ions and resistive layer damping on the stability of the resistive wall mode

“…In this work, we perform a systematic investigation of the RWM stability, by considering both the resistive layer physics and the drift kinetic damping from energetic ions. This expands the investigation reported in a recent work, 30 in terms of both the dispersion relation for the mode and the numerical results.…”

“…Unlike Ref. 30, here we shall consider two layer models for D 0 , which have been conventionally assumed in literatures for the RWM study. 13,[27][28][29]31 The first is the tearing mode dispersion relation including the toroidal favorable curvature effect.…”

“…Vice versa, in the presence of the resistive layer damping but without the drift kinetic effects, a matching procedure between the outer and the inner layer solutions is often applied to construct the resistive plasma RWM dispersion relation, 29 which is shown to be equivalent to the energy perturbation based form. 30 However, no rigorous derivation is available for Eq. (5), when both the kinetic effects and the resistive layer damping physics are present in the model, though similar approach has also been used in studying the resistive fishbone mode.…”

Effects of parallel sound wave damping and drift kinetic damping on the resistive wall mode stability with various plasma rotation profiles

“…2012), the synergetic effect with the resistive layer damping (He et al. 2014) and the three-dimensional drift kinetic response of high-b plasma in the DIII-D tokamak (Wang et al. 2015).…”

Flow-Induced New Channels of Energy Exchange in Multi-Scale Plasma Dynamics – Revisiting Perturbative Hybrid Kinetic-MHD Theory

“…Recently, the kinetic-MHD theory has been extensively studied. For example, it has been extended to include the energetic particle effects 7 8 , the resistive layer effect 9 , the plasma inertia effect 10 , the three-dimensional response 11 , and generalised to invoke the “self-consistent” approach, which includes the effect of particle kinetics on mode modification 12 . In this paper, we point out that these conventional theories have neglected the effect of macroscopic flow V a when computing P a , which means that the total pressure tensor reduces to the total stress tensor as [see equation (1) ].…”